Suggest Remedy For Knee Pain

I'm suffering from Arthritis, first my right knee and about four months ago I slipped from my stairs and the weight came on my left leg. Since then I'm having knee pain on my left leg. Somtimes I get pain on my lower left leg. I take paracetamol tablets with codeine but this does help me. This pain is continuoues. Do you think I may have broken my bone somewhere on my left leg, which causes this continuous pain? What shall I do to stop this pain.